Next chess move calculator
Set up a position or paste a FEN, and Stockfish 18 returns the strongest move along with the depth it searched to. Free, no account, and the engine runs in your browser rather than on our servers.
Best move
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How to use it
Drag pieces to reach the position you care about, or paste a FEN into the box and press Load. The evaluation bar and the best move update as the engine searches, and the depth readout tells you how far it has got. A move found at depth 6 is a first impression; the same move still on top at depth 20 is an answer.
You can also keep playing from the position. Every move you make branches into your own line, and the engine re-evaluates as you go — which is the useful part, because the question is rarely “what is best here” and usually “what happens if I try the move I actually wanted to play.”
Do not stop at the first best move
A calculator that only ever hands you one move teaches you very little. The move is the answer to a question you already had; what changes your play is understanding why the alternative you preferred does not work.
The productive loop is: decide your move before you look, then play it on the board and watch what the evaluation does. If it drops, step back and let the engine show you the refutation. That takes about thirty seconds per position and is worth more than reading a list of engine lines, because you have attached the correction to a decision you genuinely made.
Why the number moves, and what it means
The evaluation is measured in centipawns from White’s point of view: +1.00 means roughly a pawn to the good for White, and a mate score replaces it when a forced mate exists. It is a judgement about the position with best play from both sides, not a prediction about the game in front of you.
This matters at club level more than most engine tools admit. A position the engine calls +0.4 may be far easier to play than one it calls +0.9, because the plan is obvious in the first and requires a series of only-moves in the second. Use the number to find the moments where something actually changed, then judge playability yourself.
Where the explanation comes from
When a recognised principle applies — a piece is hanging, a threat needs meeting, an outpost is available — the panel names it. That text is produced by a deterministic rule engine reading the board, not by a language model writing plausible-sounding chess. The rules are allowed to be silent, and most of the time they are: on our own measurement corpus the card says nothing at all in roughly seven positions out of ten.
That silence is deliberate. A principle that fires on every position is decoration. One that fires only when the board genuinely supports it can be trusted the rest of the time, and the engine still holds a veto over anything the rules propose.
A note on fair play
Engine assistance during a live rated game is cheating, and every major platform detects it and closes accounts for it. Use this after the game or on positions you have set up to study. Nothing here is worth a banned account.
Frequently asked questions
- Is this next chess move calculator free?
- Yes, and there is no account, no daily limit, and no paid tier gating the depth. The engine is a WebAssembly build of Stockfish 18 that runs on your own machine, so serving you an extra position costs us nothing.
- Does my position get uploaded anywhere?
- No. The engine runs in a web worker inside your browser. Your position never leaves the device, which is also why the tool keeps working if you go offline after the page loads.
- How strong is the engine?
- Stockfish 18 is far stronger than any human player. The practical limit is search depth, not strength — and this page shows you the depth it reached rather than hiding it, so you can tell a settled answer from a first guess.
- Can I use this during a live game?
- No. Using an engine during a rated game is cheating on every major site and will get your account closed. This is a tool for reviewing positions after the game, or for studying a position you have set up deliberately.
- Why does the best move sometimes change as I watch?
- The engine streams results as it searches deeper. A move that looks best at depth 8 can be refuted at depth 18. That is why the depth readout matters: judge the answer by the depth it was found at.
- What is the difference between the best move and the explanation?
- The best move is whatever the engine scores highest. The explanation beneath it comes from a separate deterministic rule engine that only speaks when a named chess principle actually applies to the position, and it stays silent rather than inventing a reason.
One position is a spot check. If you want to know which mistakes keep costing you rating across a whole set of games, run the review over your own.
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